The galaxy, hung in the most beautiful works of art in the universe – is often captured by the famous “Eye of the Universe” such as the Hubble Space Telescope and the Newton Satellite, and is fascinated by people who like to look up at the stars.
▲ M51 spiral galaxy, a typical spiral galaxy.
▲NGC1300, a typical barred spiral galaxy.
You may be shocked by the brilliance of the spiral galaxy, or you may be admired by the galaxy’s Chi Mei, but you may not have seen the galaxy with two rings inside and outside. It should be noted that the spiral arm is the standard structure of most galaxies, but the ring structure is relatively rare, and in particular it also has two rings!
▲ This is the galaxy with two ring structures – NGC1512.
Let’s take a look at its resume: It is a barred galaxy, located in the clock seat, 38 million light-years away from us. It was first discovered by astronomers in 1826.
Why is it called NGC1512?
NGC is an acronym for the New General Catalogue of Nebulae and Clusters of Stars. It is a catalogue of deep space objects well-known in astronomy. The latest revision of the Catalogue in 2009 included a total of 7,840 celestial bodies, of which the 1512 celestial body was the protagonist of the current period. This indicates that it was discovered earlier (1826). NGC1512, which is the number of astronomical astronomers gave it.
The question is, what are these two ring structures of NGC1512?
In simple terms, it is the birthplace of stars, or the stellar incubation zone. It is estimated that this galaxy contains billions of stars and a large number of new stars. When one mentions the birthplace of a star, someone may immediately think of the famous “column of creation.”
Right – this is the best known Hubble Space Telescope, the most eye-catching local nebula of the Eagle Nebula. In other words, this is the main area where stars are hatched, born and evolved.
Why does a bright blue band appear? Because the newly born stars will produce a lot of strong radiation, release a huge amount of hydrogen gas, and then processed by the Hubble telescope image technology, showing a bright blue light.
Why does it have rare inner and outer double rings?
Astronomers explained that this ring structure may be caused by the asymmetry of the galaxy itself due to its long-term evolution.
How to understand? In other words, NGC 1512 does not have the symmetric spiral arm structure of most barred spiral galaxies. On the contrary, the density of matter in the outer disk and core area of the galaxy is large and the middle density is small, resulting in a high rate of star formation in the two ring belts. The more stars are formed, the greater the gravitational effect they generate, which in turn enhances the stellar birth rate in the outer disk and core area. Therefore, it can be photographed by the Hubble Space Telescope, a giant eye of space.
Inside and outside the double ring seems to have connectivity? indeed so. There are two rotating dust bands connected between the double rings, which is the trajectory of the galaxy’s spin formation.
Let us zoom in on the inner ring to see if there is any secret in it.
In addition to the blue band that belongs to the birth belt of stars, the galaxy’s core hides a large black hole, just like our galactic center. This is the result of astronomers’ comprehensive observational data such as celestial mechanics and spectroscopy.
It seems that almost every galaxy has a greedy heart.
In fact, this double-ringed galaxy is indeed greedy – relying on its own powerful gravity, it is starting a tug of war with its neighbor NGC1510, a dwarf galaxy.
Astronomers have discovered that these two galaxies have even fought 400 million years! However, the end result is only one: like the outcome of all galaxy fierce fighting, big fish eat small fish!